000 WTPZ45 KNHC 162038 TCDEP5 HURRICANE RICK DISCUSSION NUMBER 5 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP202009 200 PM PDT FRI OCT 16 2009 RICK IS RAPIDLY INTENSIFYING...WITH THE ESTIMATED INTENSITY INCREASING 40-45 KT SINCE THIS TIME YESTERDAY. MICROWAVE IMAGERY NEAR 14Z SHOWED AN EYE AND EYEWALL FORMING...AND THE EYE HAS OCCASIONALLY APPEARED IN VISIBLE IMAGERY. THE INITIAL INTENSITY IS INCREASED TO 75 KT BASED ON 18Z SATELLITE INTENSITY ESTIMATES OF 77 KT FROM TAFB AND 65 KT FROM SAB. THE CIRRUS OUTFLOW IS CURRENTLY GOOD TO EXCELLENT IN ALL DIRECTIONS. THE INITIAL MOTION IS 285/8. THE HURRICANE REMAINS ON THE SOUTH SIDE OF A DEEP-LAYER RIDGE OVER MEXICO AND THE NORTHEASTERN PACIFIC...AND THE LARGE-SCALE MODELS SUGGEST THIS SHOULD BE THE CASE FOR THE NEXT 48-72 HRS. DURING THAT TIME...THE NEW TRACK FORECAST IS AN UPDATE OF THE PREVIOUS FORECAST...CALLING FOR A WEST-NORTHWESTWARD MOTION ALONG A TRACK JUST SOUTH OF THE CONSENSUS MODELS. AFTER 72 HR...THE RIDGE IS FORECAST TO WEAKEN AS A MID/UPPER-LEVEL TROUGH DEVELOPS OVER THE SOUTHWESTERN UNITED STATES. THE TRACK FORECASTS BECOME DIVERGENT AT THAT POINT. THE GFDL...HWRF...ECMWF...AND CANADIAN MODELS SHOW RECURVATURE TO THE NORTH-NORTHEAST...WITH THE GFDL SHOWING LANDFALL IN BAJA CALIFORNIA BEFORE 120 HRS. THE NOGAPS...GFS...AND GFDN MODELS SHOW A TURN TO THE NORTH AND A SLOWER FORWARD SPEED. THE UKMET FORECASTS A CONTINUED WEST-NORTHWESTWARD MOTION...WHICH LOOKS SUSPECT AS IT APPEARS THE MODEL PREMATURELY SHEARS OFF THE TOP OF RICK. OVERALL...THE GUIDANCE ENVELOPE HAS SHIFTED A LITTLE TO THE RIGHT AFTER 72 HR...AND THE OFFICIAL FORECAST HAS FOLLOWED SUIT. THE TRACK FORECAST AFTER 72 HRS LIES JUST TO THE EAST OF THE VARIOUS CONSENSUS MODELS. RICK REMAINS EMBEDDED IN A LOW VERTICAL WIND SHEAR ENVIRONMENT OVER SEA SURFACE TEMPERATURES OF NEAR 30C...AND THIS ENVIRONMENT SHOULD CONTINUE FOR THE NEXT 48 HRS OR SO. ALL GUIDANCE FORECASTS CONTINUED STRENGTHENING...WITH THE HWRF AND GFDL MODELS FORECASTING PEAK INTENSITIES NEAR 125 KT IN ABOUT 48 HR. THE NEW INTENSITY FORECAST CALLS FOR RAPID STRENGTHENING...WITH A PEAK INTENSITY OF 125 KT IN 48 HRS IN AGREEMENT WITH THE GFDL AND HWRF. HOWEVER... RICK HAS DEVELOPED FASTER THAN ANY OF THE GUIDANCE HAS FORECAST... AND THAT TREND COULD CONTINUE FOR THE NEXT 48 HRS. UNLESS DEVELOPMENT IS INTERRUPTED BY AN EYEWALL REPLACEMENT CYCLE...AN ALTERNATIVE FORECAST SCENARIO IS THAT RICK CONTINUES TO STRENGTHEN UNTIL IT APPROACHES THE MAXIMUM POTENTIAL INTENSITY FOR THAT AREA...WHICH IS CATEGORY FIVE STRENGTH. REGARDLESS OF THE PEAK INTENSITY...AFTER 48-72 HRS RICK SHOULD MOVE OVER COOLER SEA SURFACE TEMPERATURES AND ENCOUNTER STRONGER SHEAR...WHICH SHOULD START A WEAKENING TREND. FORECAST POSITIONS AND MAX WINDS INITIAL 16/2100Z 13.0N 100.0W 75 KT 12HR VT 17/0600Z 13.2N 101.3W 90 KT 24HR VT 17/1800Z 13.7N 103.3W 105 KT 36HR VT 18/0600Z 14.3N 105.8W 115 KT 48HR VT 18/1800Z 15.0N 108.1W 125 KT 72HR VT 19/1800Z 16.5N 111.5W 120 KT 96HR VT 20/1800Z 18.5N 113.0W 105 KT 120HR VT 21/1800Z 20.5N 113.0W 85 KT $$ FORECASTER BEVEN